"A classroom is a place of friendship, of work, of courtesy, a place of life," says the hero of the deeply pleasurable French Canadian drama "Monsieur Lazhar." The courtly, correct Algerian immigrant appears as if by magic in a grade-school administrator's office after a teacher's suicide leaves the students frozen in grief.

He's a dedicated educator whose assumptions about Quebeçois culture and curriculum can be a bit off the mark. He lightly cuffs a boy who's being a jerk, tenderly pats a student's head or shoulder here or there, and assigns writing tests from demanding novels that aren't on the list. He's unsure whether to break up a snowpile game of King of the Hill or let the horseplay run its course. He marvels at Rice Krispie squares, too polite to show how appalled he is.

Lazhar embraces his class with a warmth that's missing from classrooms where cautions of "no personal contact" between kids and teachers are the rule. Best to view the students as radioactive waste, his colleagues caution: Hands off or you'll get burned.

The film's Montreal is a city of immigrants, but it's not just the newcomers who are coping with troubled lives. This student has an absent father and an airline pilot mother who is rarely around. That boy's grandfather was martyred in Chile. Another is carrying the shock of finding his dead teacher. Lazhar (played with captivating dignity and tenderness by Mohamed Fellag) is coping with a tragedy of his own that makes his compassion for the children in his care all the more heroic.

The film is rich in naturalistic, tossed-off details. A flirtation initiated by another teacher peters out in a manner that plays into the secret of Lazhar's background. His initial reluctance to be photographed in his students' class picture provides another clue. He shields his students from his own history, which we learn gradually as the film unfolds. But writer/director Philippe Falardeau isn't constructing a mystery about Lazhar's origins. He's telling an understated, warmly sentimental story about the way a generous spirit can heal a world shot through with random tragedy. Fellag makes the man an unforgettable mentor, and the flawless ensemble makes "Monsieur Lazhar" a superior film.